1. Field of the Invention
The present invention relates to horizontal decanter centrifuges. More particularly, the present invention relates to solids discharge ends for a horizontal decanter centrifuge. Even more particularly, the present invention relates to wear inserts for the solids discharge ends of a horizontal decanter centrifuge
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
A decanting centrifuge is commonly used for separating solid matter from a solids-laden liquid. For example, drilling mud with solids entrained therein must be effectively cleaned so that the drilling mud can be recycled. For another example, many manufacturing and food processing systems use vast quantities of water. In such systems, the water picks up solid waste matter which must be removed from the water before it can be discharged, whether it is into the environment or into storage. Decanter centrifuges have proved to be effective and efficient in carrying out this function of removing the solids from the recyclable liquid.
Generally, a decanter centrifuge comprises a cylindrical or frustoconical bowl rotating in one direction and at a particular although variable speed, and a screw conveyor rotating in the same direction but at a different speed. The difference in the speeds of the bowl and the screw conveyor is commonly known in the art as the differential speed.
In a well known decanting centrifuge structure, liquid which is to be clarified enters an inlet to the centrifuge where it is brought up to rotational speed around the interior surface of the bowl. Heavier elements, i.e. solids, are brought to the interior surface of the bowl by centrifugal force (furthest from the axis of rotation), while lighter elements, i.e. water or drilling fluid, remains closer to the axis of rotation of the centrifuge. The screw conveyor, rotating at a speed slightly slower than that of the bowl, conveys the solids toward a beach in a conical portion of the bowl.
Various patents have issued in the past relating to decanter centrifuges and other centrifuges. For example, U.S. Pat. No. 7,114,360 issued on Dec. 5, 2006 to Zonneveld. The patent describes a centrifuge concentrator bowl having a plurality of fluidized recesses at axially spaced positions along the peripheral wall. Each recess is defined by two side walls which has water injection holes for fluidizing materials collecting in the recess. Some of the recesses are at least partly defined by a removable insert member arranged to be attached to a suitable mounting on the wall of the bowl. Each insert member includes a face portion defining a surface facing toward the axis of the bowl for engaging the slurry and preventing wear. The face portion may include a side portion on one side or both sides located radially inwardly of a rib on a respective side of the recess and at least partly covering the rib so as to prevent the slurry from contacting the rib and causing wear to the rib.
U.S. Pat. No. 7,001,324, issued on Feb. 21, 2006 to Hensley, describes a method of retrofitting a decanting centrifuge. The method includes disassembling a known centrifuge and replacing a bowl section of the centrifuge outer body with a longer bowl section. The method further comprises replacing the conical beach section with a shorter beach section, i.e. a beach section having a greater slope. The screw conveyor is replaced with another screw conveyor having outlet nozzles adapted to impart rotational movement to the inlet feed. The retrofitted centrifuge provides enhanced performance through an additional length of cylindrical section, thereby making the clarification length longer, and improving the effectiveness of the centrifuge in removing solids from the inlet feed. The retrofitted centrifuge preferably remains mounted to the same pedestal as the centrifuge prior to retrofit.
U.S. Pat. No. 4,482,344, issued on Nov. 13, 1984 to Zettier, describes a centrifuge drum for clarifying and separating liquids. The centrifuge consists of a bottom, a cover, and a closure ring that unites them. The liquid being centrifuged is conveyed through an inlet pipe to an inlet chamber. Bores extend from the inlet chamber down to a surface that demarcates the bottom of the drum. Each bore is provided with an insert in the form of a choking device that has an outlet channel Each outlet channel empties into a vestibule. The vestibules communicate with rising channels in a disk stack. The distributor and the bottom of the drum can be in one piece.
U.S. Pat. No. 4,416,656 issued on Nov. 22, 1983 to Shapiro, teaches a hard surfacing for a centrifuge conveyor. The centrifuge conveyor is provided with hard surfacing wherein assemblies of backing members and wear-resistant members are welded by the backing member to the conveyor. An assembly may be made unitary by providing a hole in either or both of the wear-resistant member and the backing member and securing them with means extending through the hole or holes. In the event that repair is necessary, an individual assembly may be replaced by welding technique, or the backing tile may be left in place and only the wear-resistant member replaced by removing and replacing the securing means. Each fragile wear-resistant member is braced against deflection at its outer portion through its backing member to the conveyor. The embodiments employ a plurality of wear-resistant members, each such member being accurately pressed from sintered tungsten carbide.
U.S. Pat. No. 3,764,062 issued on Oct. 9, 1973 to Brautigam, teaches a centrifuge apparatus. A helical screw conveyor of the centrifuge is provided with wear-resistant surfacing having a pre-formed backing tile of the same material as the conveyor, sub-assembled with a wear-resistant member and welded to the conveyor.
U.S. Pat. No. 5,244,584 issued on Sep. 14, 1993 to Schlieperskoetter, teaches a centrifuge with wear resistant openings. The method and apparatus is for the separation of a slurry into a light fraction and a heavier fraction with a rotatable drum separator having a rotatable worm therein driven independently of the drum with an inlet for the slurry into the drum, an outlet for a liquid fraction, and outlet openings adjacent one end of the drum such as in the conical portion for the removal of the heavier abrasive sludge fraction with the openings extending at an angle opposite the direction of rotation of the drum and having wear-resistant inserts in the opening attached to webs beside the openings and removable by being pivoted out through the openings.
International Publication WO 03/076078 published on Sep. 18, 2003, and describes a decanter centrifuge with a wear reinforcement inlet. The decanter centrifuge has a hollow, rotatable drum with a screw conveyor comprising a core body, in which an inlet opening for material into the drum from an inlet chamber is provided, the inlet opening having a delimitation surface which is rear relative to the direction of rotation and extending substantially axially, the delimitation surface being provided with a wear reinforcement member. The wear reinforcement member extends along the rear delimitation surface into the inlet chamber. The wear reinforcement member is provided with abutment surfaces in abutment against abutment surfaces associated with the core body, which during operation prevents the wear reinforcement member from moving tangentially forwards in the direction of rotation and radially out of the core body. At least one of said abutment surfaces associated with the core body is constituted by a removable blocking member. The wear reinforcement member and the inlet opening are designed in such a manner that the wear reinforcement member can be introduced to its operating from the exterior side of the core body.
It is an object of the present invention to provide a wear insert for the solids discharge end of a horizontal decanter centrifuge.
It is an object of the present invention to provide a wear insert for the solids discharge end of a horizontal decanter centrifuge that can be bolted in from the outside of the centrifuge.
It is another object of the present invention to provide a wear insert for the solids discharge end of a horizontal decanter centrifuge that is constructed of carbide.
It is another object of the present invention to provide a wear insert for the solids discharge end of a horizontal decanter centrifuge that is a direct bolt-on attachment for existing machines in the market.
It is another object of the present invention to provide a wear insert for the solids discharge end of a horizontal decanter centrifuge which prevents the escape of solids through unintended directions.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.